This research application is in response to the Program Announcement "National Chimpanzee Breeding nd Research Program", and is a companion to the proposal for the breeding program from The University of Texas, M. D. Anderson Cancer Center, Science Park, Department of Veterinary Sciences. The long-term objective of this behavioral research program is to improve the care and management of captive chimpanzees by conducting quantitative studies of applied behavioral issues. These studies are designed and will be completed in close collaboration with the chimpanzee breeding program and these studies address issues that are critical to colony behavioral management in the next five years. The proposed behavioral research incorporates novel advances in four areas of environmental improvement for chimpanzees that have not previously been addressed. (1) Human-chimpanzee interactions will be evaluated as environmental enrichment using positive reinforcement training as the mechanism of interaction. The potential for training to reduce stress associated with a common animal care and management procedure will be tested using physiological and behavioral measures of stress for the chimpanzees and their human care givers. (2) The roles of cognitive stimulation, predictability and control in chimpanzee enrichment will be measured. Computerized problems will be set for the chimpanzees to learn at their own pace. Well-being issues related to the predictable nature of animal care routines and increased control over environmental stimulation will be studied. (3) Behavioral management techniques will be used to try to reduce the weight of obese chimpanzees, while maintaining their well-being. And (4) Problems related to managing social behavior while colony production goals are being reduced (as mandated from NCRR) will be studied. The impact of having fewer infants in groups will be measured on young mothers who were reared with differing amounts of exposure to infants. A process for forming new chimpanzee groups will be documented, including determining whether initial reactions between pairs of chimpanzees predict their future relationships. In addition, one project continuing from the last grant period will be completed, comparing behavioral development of young chimpanzees in four different social settings to determine optimal socialization strategies. The studies proposed in this application are objective, quantitative evaluations of methods to improve the care and production of captive chimpanzees.These investigations are essential to developing valid criteria for regulating chimpanzee well-being and meeting the societal desire for improving the care of laboratory primates.